This invention relates generally to the field of sheet metal fabrication, and more particularly to improved methods and techniques for forming the component parts of such products as merchandise display devices having relatively movable component parts, such as those disclosed in the above-mentioned related application.
In that application, there is disclosed a merchandise display device having elongated trays for supporting articles of merchandise packaged in relatively flat rectangular containers, the trays having means for advancement as the lead package in a stack is manually removed. The disclosed device is characterized in the provision of a negator spring, the free end of which is connected to a nylon cord threaded through an opening in a forward end of the tray to be looped back upon itself and secured to a slideably mounted follower on the floor of the tray. In this manner, the advantage of a negator spring, e.g. a constant pulling force is translated to a constant pushing force on the rearwardmost of the stack of packages. The follower employed for this purpose is supported within a slot in the floor of the tray forming a track. The negator spring, in extended condition, moves beneath the slot. A typical device will include any number of such trays.
To avoid axial curling of the negator spring which would render the same inoperative, it is desirable to provide guiding means at periodic intervals along the path of travel. It is also desirable to provide means to prevent the fraying of the nylon cord which interconnects the negator spring to the sliding follower which advances the packages in the tray.